get_reference

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description fully discloses behavior: dependency on phone's reference mode (LIVE, Capture, File), handling of non-image files, return format, and storage location (Downloads folder, not temp). It also warns against reusing stale copies.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Every sentence adds value. The description is front-loaded with the core action, then details modes and return values. No redundancy or unnecessary words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given zero parameters and the existence of an output schema, the description explains the output fields (path, mime, bytes, name) and covers edge cases like non-image files and different modes. It provides complete context for using the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has zero parameters (100% coverage). Since there are no parameters, the description does not need to add parameter semantics; it correctly focuses on behavior.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool downloads the phone's current 'share target' to the PC, saves it, and returns path and metadata. It explicitly distinguishes from sibling tool 'get_live_frame' by noting the latter is simpler for image previews only.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context on when to use (to fetch the current designation) and when not to (avoid reusing stale files). It mentions an alternative ('get_live_frame') but does not address other siblings like 'get_cam_fps' or 'read_sensors'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.